Virginia’s 7th Congressional District is one of the most closely watched toss-up races in the country. If Democrats are going to win in a “Blue Wave,” this race will be one of the earliest indicators.

Incumbent Rep. Dave Brat, R-Va., is running for re-election in a district Republicans have held since 1971. When Brat was re-elected in 2016, he defeated his Democratic challenger by 15 points. A member of the House Freedom Caucus, Brat is most well known for his upset victory against sitting Republican House Majority Leader Eric Cantor in the 2014 Republican primary. He is a Ph.D. economist with one of the most conservative voting records in Congress.

The Democratic nominee is Abigail Spanberger, a retired CIA officer running as a moderate who is polling tightly against Brat. Spanberger has emphasized her national security credentials, made health care a top issue in her campaign, and criticized Brat for voting to repeal Obamacare.

Polling shows a significant shift in this district in the Democrats’ favor. The most recent New York Times/Sienna poll shows Brat leading Spanberger by only two points.